Method for large-scale multiple source sound reinforcement

Abstract

An improved method for transmitting sound at high power levels over a wide angle zone of dispersion without distortion, comprising the step of emitting sound waves from a plurality of individual sources, each characterized by a relatively narrow, wedge-shaped envelope of sound projection, such that adjacent edges of respective sound projection envelopes are in substantial alignment and do not overlap, whereby the absence of interference between sounds emitted from different sources precludes sound distortion and enables uniform sound dispersion and high sound quality throughout the zone. The sound waves are preferably emitted from electroacoustical loudspeakers having loudspeaker enclosures shaped to conform to the edges of their respective sound envelopes.

What is claimed is: 
     
       1. An improved method for transmitting sound at high power levels over a wide angle zone of dispersion without distortion, comprising the steps of: emitting sound waves from a plurality of individual sources, each source having a constant acoustic power output at a predetermined angle of divergence and over a predetermined frequency range covering substantially a full audio range of frequencies above approximately 125 to 500 Hz, the sources being of a constant-directivity type and characterized by a relatively narrow, wedge-shaped envelope of sound projection with an angle of sound dispersion not more than approximately forty degrees; and,   positioning the plurality of said individual sources in side-by-side relationship so that adjacent edges of respective sound projection envelopes are in substantial alignment and do not overlap, whereby the absence of interference between sounds emitted from any of the sources preclude sound distortion and enables sound dispersion and high sound quality throughout the zone.   
     
     
       2. The method of claim 1, wherein each said source has sections for distinct frequency ranges, the sections likewise emitting sound at constant-directivity over said predetermined angle of divergence. 
     
     
       3. The method of claim 2, wherein sound is emitted from a mid frequency source and a high frequency source, and further comprising the step of dividing signals into said mid frequency source and high frequency source using a cross-over network. 
     
     
       4. The method of claim 1, wherein said individual sources are electroacoustical loudspeakers having loudspeaker enclosures shaped to conform to the edges of their respective sound envelopes. 
     
     
       5. The method of claim 4, comprising the further step of forming each loudspeaker enclosure to be substantially trapezoidal in plan. 
     
     
       6. The method of claim 1, further comprising the step of emitting the sounds radially outwardly from positions on a substantially circular arc. 
     
     
       7. The method of claim 1, comprising the step of configuring each of the sound envelopes to define an angle of sound dispersion which is not more than approximately thirty degrees. 
     
     
       8. The method of claim 3, comprising the step of configuring each of the sound envelopes to define an angle of sound dispersion which is not more than approximately twenty degrees. 
     
     
       9. The method of claim 1, further comprising the steps of emitting the sound waves from two arrays of the plurality of sources and skewing the sounds emitted from the arrays to achieve stereophonic imaging throughout a large portion of the dispersion zone. 
     
     
       10. An improved method for transmitting sound at high power levels over a wide angle zone of dispersion without distortion, comprising the steps of emitting sound waves from a plurality of individual constant-directivity sources, each source having a constant acoustic power output at a predetermined angle of divergence and over a predetermined frequency range covering substantially a full audio frequency range above approximately 125 to 500 Hz, the individual sources being characterized by a relatively narrow, wedge-shaped envelope of sound projection with an angle of sound dispersion not more than approximately forty degrees, such that adjacent edges of respective sound projection envelopes are in substantial alignment and do not overlap, whereby the absence of interference between sounds emitted from different sources preclude sound distortion and enables uniform sound dispersion and high sound quality throughout the zone. 
     
     
       11. The method of claim 10, comprising the step of configuring each of the sound envelopes to define an angle of sound dispersion which is not more than approximately thirty degrees. 
     
     
       12. The method of claim 11, comprising the step of configuring each of the sound envelopes to define an angle of sound dispersion which is not more than approximately twenty degrees. 
     
     
       13. The method of claim 10, wherein the sources are electroacoustical loudspeakers having loudspeaker enclosures shaped to conform to the edges of their respective sound envelopes. 
     
     
       14. The method of claim 13, comprising the further step of forming each loudspeaker enclosure to be substantially trapezoidal in plan. 
     
     
       15. The method of claim 10, further comprising the step of emitting the sounds radially outwardly from positions on a substantially circular arc. 
     
     
       16. The method of claim 10, further comprising the steps of emitting the sound waves from two arrays of the plurality of sources and skewing the sounds emitted from the arrays to achieve stereophonic imaging throughout a large portion of the dispersion zone. 
     
     
       17. The method of claim 10, wherein each said source has sections for distinct frequency ranges, the sections likewise emitting sound at constant-directivity over said predetermined angle of divergence. 
     
     
       18. The method of claim 17, wherein sound is emitted from a mid frequency source and a high frequency source, and further comprising the step of dividing signals into said mid frequency source and high frequency source using a cross-over network.